This article is from the Epilepsy FAQ, by Andrew Patrick (firstname.lastname@example.org) with numerous contributions by others.
Most epileptic seizures are controlled by special anti-convulsive drugs
prescribed by a physician. About 50 per cent of those who take this
medication will have their seizures eliminated; 30 per cent will have
their seizures reduced in intensity and frequency to the point where
they can live and work normally. The remaining 20 per cent are either
resistant to the medication, or else they require such large dosages of
the drug to control the seizures that it is preferable to accept